Then, several glycoforms of PSA in serum to distinguish patients with prostate cancer from those with BPH were discovered: differential binding of PSA in serum to Maackia amurensis (MAA), a lectin that recognizes terminal α2-3 sialylation, by Ohyama et al.[45], and alpha1,2-fucosylated and beta-N-acetylgalactosaminylated PSA, by Fukushima et al.[46]. Here, KLK3 is linked to prostate cancer.